Windows 8.1.1 RT - Some app disappeared and other broken

Hi!

I'm posting here because I have an issuesince yesterday night: lots of my apps deleted themselves without me doing anything, and some other (the Microsoft ones: weather, bing news etc, plus Flipboard) are just broken. When I try to open them, there's a page of the color of the app (red for news, light blue for weather......) without the app's logo and then it comes back to start screen.
I also tried to download them again from the store, and this is what happen. Under the "instal" button there's a message: "You already have this app. You can download to this computer", which it's ok, but if I click on Install, notification appears on the top right; tapping on it doesn't do anything, and the app isn't in the app folder.
When I uninstalled and re-installed Weather (which wasn't disappeared, but broken) the app worked again.

The only "weird" thing that I remember I have done is to empty the bin, as I had memory full and wanted to gain some space.

Do you think this can be a malware? How do you think I can fix that?

I already tried to open a new account, and it works just fine; I with to fix the current o ne, thoug, for understandable reasons.

I'm open to every solution!

Thanks :)

Umb